1c. Synaptic Transmission Flashcards
Electrical Transmission
- 3 Locations
- CNS synapses
- Cardiac myocytes
- Some retinal cells
Electrical Transmission
- 3 Disadvantages
- Need a large presynaptic terminal to get depolarisation
- Bidirectional signalling
- Limited range of information communicated
Electrical Transmission
- 1 Advantage
- Rapid
Chemical Transmission
- Advantages
- Unidirectional signalling
- Wide range of information communicated
Amino Acid Neurotransmitters
- 3
- Glutamate
- GABA
- Glycine
Glutamate
- Receptors
Ionotrophic receptors:
- AMPA
- NMDA
Metabotrophic receptors:
- MGluR 1-5
Glutamate
- Transmitter Type
Amino acid neurotransmitter
GABA
- Receptors
Ionotrophic receptors:
- GABA-A receptor
Metabotrophic receptors
- GABA-B receptor
GABA
- Transmitter Type
Amino acid neurotransmitter
Glycine
- Receptors
Ionotrophic receptors:
- Glycine receptor
No metabotrophic receptor
Glycine
- Transmitter Type
Amino acid neurotransmitter
Biogenic Amine Neurotransmitters
- 5
- Acetylcholine
- Noradrenaline
- Dopamine
- Serotonin
- Histamine
Acetylcholine
- Transmitter type
Biogenic amine
Acetylcholine
- Receptors
Ionotrophic receptors:
- Nicotinic
Metabotrophic receptors
- Muscarinic 1-5
Glutamate
- Role
Major CNS excitatory neurotransmitter
GABA
- Role
Inhibitory neurotransmitter
Glycine
- Role
Spinal cord inhibitory neurotransmitter
Noradrenaline
- Transmitter Type
Biogenic amine
Noradrenaline
- Receptors
No ionotrophic receptors
Metabotrophic receptors:
- α 1-2
- β 1-2
Noradrenaline
- Location
Locus coeruleus
Dopamine
- Transmitter Type
Biogenic amine
Dopamine
- Receptors
No ionotrophic receptors
Metabotrophic receptors:
- D1 receptor
- D2 receptor
Dopamine
- Location
Substantia nigra via cAMP
Serotonin
- Transmitter Type
Biogenic amine
Serotonin
- Receptors
Ionotrophic receptors:
- 5-HT3 receptor
Metabotrophic receptors:
- 5-HT1
- 5-HT2
- 5-HT4
Serotonin
- Location
Raphe nucleus
Histamine
- Receptors
No ionotrophic receptors
Metabotrophic receptors
- H1-4
Purine Neurotransmitters
- 2
- ATP
- Adenosine
ATP
- Transmitter Type
Purine neurotransmitter
Adenosine
- Transmitter Type
Purine neurotransmitter
ATP
- Receptors
Ionotrophic receptors
- P2X receptors
Metabotrophic receptors
- P1Y
- P2Y
ATP
- Roles
- Vascular apoptosis
- Cytokine roles
Adenosine
- Receptors
No ionotrophic receptors
Metabotrophic receptors
- A1-3
Adenosine
- Role
Cardiovascular roles
Neuropeptide Neurotransmitters
- 7
- Opioids
- Pituitary
- Secretins
- Insulins
- Tachykinins
- Somatostatins
- Gastrins
Gaseotransmitters
- 3
- NO
- CO
- H2S
NO
- Receptors
No ionotrophic receptors
Metabotrophic receptor
- Soluble guanylyl cyclase
CO
- receptors
No ionotrophic receptors
Metabotrophic receptor
- Soluble guanylyl cyclase
NO
- Role
Endothelium-derived relaxing factor
G-Protein Coupled Receptors
- 2 Advantages
- Amplification
- Versatility in intracellular cascade
AMPA vs NMDA Receptors
- Speed
AMPA = fast NMDA = slow
AMPA vs NMDA Receptors
- Kinetics
AMPA obeys ohm’s law
NMDA doesn’t obey ohm’s law
AMPA vs NMDA Receptors
- Ions
Relatively unselective for Na+ and K+
AMPA vs NMDA Receptors
- Reversal potential
Close to and slightly positive of 0mV
NMDA Receptors
- Non-Linear Kinetics
Near-linear near reversal potential
Not linear near resting potential
- Mg2+ ions block the channel at resting potential, reducing cation influx
- Depolarisation draws Mg2+ ions away from the pore, allowing cation influx
